# ============================================================
# File: scraper/services/init_service.py
# Purpose:
#   Orchestrate INIT-flow:
#     - resolve site
#     - fetch minimal metadata
#     - derive book_id
#     - register in SQLite
#     - store main cover
# ============================================================

import re
from scraper.services.site_resolver import SiteResolver
from scraper.services.scrape_engine import ScrapeEngine
from scraper.services.cover_service import CoverService

from db.repository import register_book


class InitService:

    @staticmethod
    def derive_book_id(url: str) -> str:
        """
        PTWXZ URL format ends with /{id}.html.
        If no match → fallback to sanitized URL.
        """
        m = re.search(r"/(\d+)\.html$", url)
        if m:
            return m.group(1)
        return url.replace("/", "_")

    @staticmethod
    def execute(url: str) -> dict:
        """
        Main INIT-flow entry point.
        Returns complete metadata + registration info.
        """

        # 1) Determine which BookSite applies
        site = SiteResolver.resolve(url)

        # 2) Metadata only (no chapters)
        meta = ScrapeEngine.fetch_metadata_only(site, url)

        title = meta.get("title") or "Unknown"
        author = meta.get("author")
        description = meta.get("description")
        cover_url = meta.get("cover_url")

        # 3) Determine book_id
        book_id = InitService.derive_book_id(url)

        # 4) SQLite registration
        register_book(
            book_id=book_id,
            title=title,
            author=author,
            description=description,
            cover_url=cover_url,
        )

        # 5) Download UI cover
        CoverService.download_main_cover(cover_url, book_id)

        # 6) Structured output for UI
        return {
            "book_id": book_id,
            "title": title,
            "author": author,
            "description": description,
            "cover_url": cover_url,
            "status": "registered",
        }